912 Å luminosity function of galaxies at ﹩z\approx 3﹩ (solid line), compared to the distribution of QSO luminosities at the same redshift (dashed line). The latter has been derived assuming a spectral slope of ﹩\alpha _{s}=0.5﹩. The former assumes a Salpeter IMF with a constant star formation rate (age is 1 Gyr): M_AB﹩( 912\,\mbox{\Å} ) =-19﹩ corresponds to a rate of 13 M_⊙ yr⁻¹. The solid and dashed lines represent functional fits to the data points, and the dotted lines represent their extrapolation.